CURIOSITIES RESPECTING VARIOUS PHENOMENA OR APPEARANCES IN NATURE.—(Continued.)

Extraordinary Properties and Effects of Lightning.—A very surprising property of lightning of the zigzag kind, especially when near, is, its seeming omnipresence. If two persons are standing in a room looking different ways, and a loud clap of thunder, accompanied with zigzag lightning, happens, they will both distinctly see the flash, not only by that indistinct illumination of the atmosphere which is occasioned by fire of any kind, but the very form of the lightning itself, and every angle it makes in its course, will be as distinctly perceptible as if both had looked directly at the cloud from whence it proceeded. If a person happened at that time to be looking on a book, or other object which he held in his hand, he would distinctly see the form of the lightning between him and the object at which he looked. This property seems peculiar to lightning, and to belong to no other kind of fire whatever. In August 1763, a most violent storm of thunder, rain, and hail, happened at London, which did damage in the adjacent country to the amount of £50,000. Hailstones fell of an immense size, from two to ten inches in circumference, but the most surprising circumstance attending the hurricane was, the sudden flux and reflux of the tide in Plymouth pool, exactly corresponding with the like agitation in the same place, at the time of the great earthquake at Lisbon. Instances have also occurred where lightning, by its own proper force, without any assistance from those less common agitations of the atmosphere or electric fluid, has thrown stones of immense weight to considerable distances; torn up trees by the roots, and broke them in pieces; shattered rocks; beat down houses, and set them on fire, &c. The following singular effect of lightning, upon a pied bullock, is recorded in the sixty-sixth volume of the Philosophical Transactions.—

“In the evening of Sunday the 28th of August, 1774, there was an appearance of a thunder storm, but we heard no report. A gentleman who was riding near the marshes not far from this town, (Lewes) saw two strong flashes of lightning running along the ground of the marsh, at about nine o’clock P. M. On Monday morning, when the servants of Mr. Roger, a farmer at Swanborough, went into the marsh to fetch the oxen to their work, they found one of them, a four-year-old steer, standing up, to appearance much burnt, and so weak as to be scarcely able to walk. The animal seemed to have been struck by lightning in a very extraordinary manner. He was of a white and red colour; the white in large marks, beginning at the rump bone, and running in various directions along both sides; the belly was all white, and the whole head and horns white likewise. The lightning, with which he must have been undoubtedly struck, fell upon the rump bone, which was white, and distributed itself along the sides in such a manner as to take off all the hair from the white marks as low as the bottom of the ribs, but so as to leave a list of white hair, about half an inch broad, all round where it joined to the red, and not a single hair of the red appears to have been touched. The whole belly was unhurt, but the end of the sheath of the penis had the hair taken off; it was also taken off from the dewlap: the horns and the curled hair on the forehead were uninjured; but the hair was taken off from the sides of the face, from the flat part of the jaw-bones, and from the front of the face, in stripes. There were a few white marks on the side and neck, which were surrounded with red; and the hair was taken off from them, leaving half an inch of white adjoining to the red. The farmer anointed the ox with oil for a fortnight; the animal purged very much at first, and was greatly reduced in flesh, but afterwards recovered.” In another account of this accident, the author supposes that the bullock had been lying down at the time he was struck; which shews the reason that the under parts were not touched. “The lightning, conducted by the white hair, from the top of the back down the sides, came to the ground at the place where the white hair was left entire.”

The author of this account says, that he inquired of Mr. Tooth, a farrier, whether he ever knew of a similar accident; and that he told him “the circumstance was not new to him; that he had seen many pied bullocks struck by lightning in the same manner; that the texture of the skin under the white hair was always destroyed, though looking fair at first; but after a while it became sore, throwing out a putrid matter in pustules, like the small-pox with us, which in time falls off, when the hair grows again, and the bullocks receive no farther injury;” which was the case with the bullock in question. In a subsequent letter, however, the very same author informs us, that he had inquired of Mr. Tooth, “whether he ever saw a stroke of lightning actually fall upon a pied bullock, so as to destroy the white hair, and shew evident marks of burning, leaving the red hair uninjured? He said he never did; nor did he recollect any one that had. He gave an account, however, of a pied horse, belonging to himself, which had been struck dead by lightning in the night time.” The explosion was so violent, that Mr. Tooth imagined his house had been struck, and therefore immediately got up. On going into the stable, he found the horse almost dead, though it kept on its legs near half an hour before it expired. The horse was pied white on the shoulder, and greatest part of the head, viz. the forehead and nose, where the greatest force of the stroke came. “The hair was not burnt nor discoloured, only so loosened at the root, that it came off with the least touch. And this is the case, according to Mr. Tooth’s observation, with all that he has seen or heard of, viz. the hair is never burnt, but the skin always affected. In the horse, all the blood in the veins under the white parts of the head was quite stagnated, though he could perceive it to flow in other parts as usual; and the skin, together with one side of the tongue, was parched and dried up to a greater degree than he had ever seen before.” Another instance is mentioned of this extraordinary effect of lightning upon a bullock, in which even the small red spots on the sides were unaffected; and in this, as well as the former, the white hair on the under part of the belly, and on the legs, was left untouched.

One very singular effect of lightning is, that it has been observed to kill alternately, that is, supposing a number of people standing in a line; if the first person was killed, the second would be safe; the third would be killed, and the fourth safe; the fifth killed, &c. Effects of this kind are generally produced by the most violent kind of lightning; namely, that which appears in the form of balls, which frequently divide themselves into several parts before they strike. If one of these parts of a fire-ball strike a man, another will not strike the person who stands immediately close to him; because there is always a repulsion between bodies electrified the same way. Now, as these parts into which the balls break have all the same kind of electricity, it is evident that they must for that reason repel one another, and this repulsion is so strong, that a man may be interposed within the stroke of two of them, without being hurt by either.

Thunder Rod.—Dr. Franklin has demonstrated the identity of thunder with the electric explosion. He availed himself of many curious discoveries which he had made of electrical laws: in particular, having observed that electricity was drawn off at a great distance, and without the least violence of action, by a sharp metallic point, he proposed to philosophers to erect a tall mast or pole on the highest part of a building, and to furnish the top of it with a fine metallic point, properly insulated, with a wire leading to an insulated apparatus for exhibiting the common electrical appearances. To the whole of this contrivance he gave the name of Thunder Rod, which it still retains. He had not a proper opportunity of doing this himself, at the time of his writing his dissertation in a letter from Philadelphia to the Royal Society of London; but the contents were so scientific, and so interesting, that in a few weeks they were known over all Europe. His directions were followed in many places. In particular, the French academicians, encouraged by the presence of their monarch, and the great satisfaction which he expressed at the repetition of Dr. Franklin’s most instructive experiments, which discovered and made known the theory of positive and negative electricity, as it is now received, were eager to execute his orders, and make his grand experiment, which promised so fairly to bring this tremendous operation of nature, not only within the pole of science, but in the management of human power. But in the mean time, Dr. Franklin, impatient of delay, and perhaps incited by the honourable desire of well-deserved fame, put his own scheme in practice. His inventive mind suggested to him a method of presenting a point to a thunder cloud at a considerable distance. This was, by fixing his point on the head of a paper kite, which the wind should raise to the clouds, while the wet string that held it should serve for a conductor of the electricity. With a palpitating heart, Dr. Franklin, unknown to his neighbours, and accompanied only by his son, went into the fields, and sent up his messenger that was to bring him news from the heavens. He obtained only a few sparks from his apparatus that day; but returned to his house in a state of perfect satisfaction with his success. We may justly consider this as one of the greatest of philosophical discoveries, and as doing the highest honour to the inventor; for it was not a suggestion from an accidental observation, but arose from a scientific comparison of facts, and a sagacious application of the doctrine of positive and negative electricity; a doctrine wholly Dr. Franklin’s, and the result of the most acute and discriminating observation. It was this alone, that suggested the whole; and, by explaining to his satisfaction the curious property of sharp points, gave him the courage to handle the thunderbolt of the heavens. It is now a point fully ascertained, that thunder and lightning are the electric snap and spark, as much superior to our puny imitations as we can conceive from the immense extent of the instruments in the hands of Nature.

If (says Dr. Franklin,) a conductor, one foot thick, and five feet long, will produce such snaps as agitate the whole human frame, what may we not expect from a surface of ten thousand acres of electrified clouds? How loud must be the explosion! how terrible the effects!

To this wonderful discovery, Dr. Darwin alludes in the following lines:—

Led by the phosphor light, with daring tread
Immortal Franklin sought the fiery bed;
Where, nurs’d in night, incumbent tempest shrouds
The seeds of thunder in circumfluent clouds,
Besieg’d with iron points his airy cell,
And pierc’d the monster slumb’ring in his shell.

Fire Balls,—are a kind of luminous bodies, commonly appearing at a great height above the earth, with a splendour surpassing that of the moon, and sometimes equalling her apparent size. They generally proceed in this hemisphere from north to south with vast velocity, frequently breaking into several smaller ones, sometimes vanishing with a report, and sometimes not. These luminous appearances, no doubt, constitute one branch of the ancient prodigies, or blazing stars. They sometimes resemble comets, in being attended with a train; but frequently they appear with a round well-defined disk. The first of these, of which we have any accurate account, was observed by Dr. Halley and others, at different places, in 1719. From the slight observations they could take of its course among the stars, its perpendicular height was computed at about seventy miles from the surface of the earth. The height of others has also been computed, and found to be various; though in general it is supposed to be beyond the limits assigned to our atmosphere, or where it loses its refractive power. The most remarkable of these on record appeared on the 18th of August, 1783, about nine o’clock in the evening. It was seen to the northward of Shetland, and took a southerly direction for an immense space, being observed as far as the southern provinces of France and Rome. During its course, it appears frequently to have changed its shape; sometimes appearing in the form of one ball, sometimes two or more; sometimes with a train, sometimes without one. It passed over Edinburgh nearly in the zenith, and had then the appearance of a well-defined round body, extremely luminous, and of a greenish colour; the light which it diffused on the ground giving likewise a greenish cast to objects. After passing the zenith, it was attended by a train of considerable length, which, continually augmenting, at last obliterated the head entirely; so that it looked like a wedge, flying with the obtuse end foremost. The motion was not apparently swift, by reason of its great height; though in reality it must have moved with great rapidity, on account of the vast space it travelled over in a short time. In other places its appearance was very different. At Greenwich, we are told, that “two bright balls, parallel to each other, led the way, the diameter of which appeared to be about two feet; these were followed by an expulsion of eight others, not elliptical, seeming gradually to fall to pieces, for the last was small. Between each two balls a luminous serrated body extended, and at the last a blaze issued, which terminated in a point. Minute particles dilated from the whole. The balls were tinted first by a pure bright light, then followed a delicate yellow, mixed with azure, red, green, &c. which, with a coalition of bolder tints, and a reflection from the other balls, gave the most beautiful rotundity and variation of colours, that the human eye could be charmed with. The sudden illumination of the atmosphere, and the form and singular transition of this bright luminary, contributed much to render it awful: nevertheless, the amazingly vivid appearance of the different balls, and other rich connecting parts, not very easy to delineate, gave an effect equal to the rainbow in the zenith of its glory.”

Terrible Effects of Electrified Clouds.—The most extraordinary instance of this kind perhaps on record, happened in the island of Java, in the East Indies, in August, 1772. On the 11th of that month, at midnight, a bright cloud was observed covering a mountain in the district called Cheribou, and at the same time several reports were heard like those of a gun. The people who dwelt on the upper parts of the mountain, not being able to fly fast enough, a great part of the cloud, almost three leagues in circumference, detached itself under them, and was seen at a distance, rising and falling like the waves of the sea, and emitting globes of fire so luminous, that the night became as clear as day. The effects of it were astonishing: every thing was destroyed for seven leagues round; the houses were demolished; plantations were buried in the earth; and two thousand one hundred and forty people lost their lives, besides fifteen hundred head of cattle, and a vast number of horses, goats, &c.

Another instance of a very destructive cloud, the electric qualities of which at present can scarcely be doubted, is related by Mr. Brydone, in his Tour through Malta. It appeared on the 29th of October, 1757. “About three-quarters of an hour after midnight, there was seen, to the south-west of the city of Valetta, a great black cloud, which, as it approached, changed its colour, till at last it became like a flame of fire mixed with black smoke. A dreadful noise was heard on its approach, which alarmed the whole city. It passed over the port, and came first on an English ship, which in an instant was torn in pieces, and nothing left but the hull; part of the masts, sails, and cordage, were carried to a considerable distance with the cloud. The small boats and selloques, that fell in its way, were all broken to pieces and sunk. The noise increased, and became more frightful. A sentinel, terrified at its approach, ran into his box; but both he and it were lifted up and carried into the sea, where he perished. It then traversed a considerable part of the city, and laid in ruins almost every thing that stood in its way. Several houses were laid level with the ground, and it did not leave one steeple in its passage. The bells of some of them, together with the spires, were carried to a considerable distance; the roofs of the churches demolished and beat down, &c. It went off at the north-east point of the city, and, demolishing the lighthouse, is said to have mounted up into the air with a frightful noise, and passed over the sea to Sicily, where it tore up some trees, and did other inconsiderable damage; but nothing material, as its fury had been spent at Malta. The number of killed and wounded amounted to near two hundred; and the loss of shipping, &c. was very considerable.”—The effects of thunder storms, and the vast quantity of electric matter formed in the clouds which produce these storms, are so well known, that it is superfluous to mention them. It appears, however, that even these clouds are not so highly electrified as to produce their fatal effects on those who are immersed in them. It is only the discharge of part of their electricity upon such bodies as are either not electrified at all, or not so highly electrified as the cloud, that does all the mischief. We have, however, only the following instance on record, of any persons’ being immersed in the body of a thunder cloud. Professor Saussure, and young Mr. Jalabert, when travelling over one of the high Alps, were caught among clouds of this kind; and, to their astonishment, found their bodies so full of electrical fire, that spontaneous flashes darted from their fingers with a crackling noise, and the same kind of sensation as when strongly electrified by art.

Among the awful phenomena of nature, none have excited more terror than lightning and thunder. Some of the profligate Roman emperors, of whom history records that they procured themselves to be deified, confessed, by their trembling and hiding themselves, when they heard the thunder, that there was a divine power greater than their own—Coela tonantem Jovem. The greatest security against the terrors of a thunder-storm, although no certain one against its effects, is that life of piety and virtue, which is the best guardian of every earthly blessing. The good man, who knows that every event is under the direction of an overruling Providence, and that this life is only a part of his existence, introductory to the blissful scenes of immortality, will behold the terrors of the storm with unshaken resolution: grateful to the Supreme Being, if permitted to escape from the danger; and acquiescing in the Divine Will, if thus to be conveyed, by an easy and instantaneous passage, to that heaven where his conversation had long been, and to that God with whom he delighted to walk.

These sentiments are beautifully expressed in the following lines, written in a midnight thunder-storm, by the celebrated Mrs. Carter, and addressed to a lady:—

Let coward guilt with pallid fear
To shelt’ring caverns fly,
And justly dread the vengeful fate
That thunders thro’ the sky:
Protected by that hand, whose law
The threat’ning storms obey,
Intrepid virtue smiles secure,
As in the blaze of day.
In the thick cloud’s tremendous gloom,
The lightning’s lurid glare,
It views the same All-gracious Pow’r,
That breathes the vernal air.
Thro’ nature’s ever-varying scene,
By diff’rent ways pursu’d,
The one eternal end of Heav’n
Is universal good.
The same unchanging mercy rules
When flaming ether glows,
As when it tunes the linnet’s voice,
Or blushes in the rose.

By reason taught to scorn those fears
That vulgar minds molest,
Let no fantastic terrors break
My dear Narcissa’s rest.
Thy life may all the tend’rest care
Of Providence defend,
And delegated angels round
Their guardian wings extend.
When thro’ creation’s vast expanse
The last dread thunders roll,
Untune the concord of the spheres,
And shake the rising soul;
Unmov’d may’st thou the final storm
Of jarring worlds survey,
That ushers in the glad serene
Of everlasting day.

The following lines on the same subject were written by Mrs. Chapone:—

In gloomy pomp, whilst awful midnight reigns,
And wide o’er earth her mournful mantle spreads;
Whilst deep-voiced thunders threaten guilty heads,
And rushing torrents drown the frighted plains;
And quick-glanc’d lightnings, to my dazzled sight,
Betray the double horrors of the night:
A solemn stillness creeps upon my soul,
And all its powers in deep attention die;
My heart forgets to beat; my stedfast eye
Catches the flying gleam; the distant roll,
Advancing gradual, swells upon my ear
With louder peals, more dreadful as more near.
Awake, my soul, from thy forgetful trance!
The storm calls loud, and meditation wakes:
How at the sound pale superstition shakes,
Whilst all her train of frantic fears advance!
Children of darkness, hence! fly far from me!
And dwell with guilt and infidelity!
But come, with look compos’d and sober pace,
Calm Contemplation, come! and hither lead
Devotion, that on earth disdains to tread;
Her inward flame illumes her glowing face,
Her upcast eye, and spreading wings, prepare
Her flight for heaven, to find her treasure there.
She sees, enraptur’d through the thickest gloom,
Celestial beauty beam, and ’midst the howl
Of warring winds, sweet music charms her soul;
She sees, while rifted oaks in flames consume,
A Father God, that o’er the storm presides,
Threatens to save,—and loves when most he chides.

Surprising Effects of Extreme Cold.—By extreme degrees of cold, trees are burst, rocks rent, and rivers and lakes frozen several feet deep: metallic substances blister the skin like red-hot iron: the air, when drawn in by respiration, hurts the lungs, and excites a cough: even the effects of fire in a great measure seem to cease; and metals, though kept for a considerable time before a strong fire, will still freeze water when thrown upon them. When the French mathematicians wintered at Tornea, in Lapland, the external air, when suddenly admitted into their rooms, converted the moisture of the air into whirls of snow; their breasts seemed to be rent when they breathed it; the contact of it was intolerable to their bodies; and the spirit of wine, which had not been highly rectified, burst some of their thermometers by the congelation of the aqueous parts.

Extreme cold very often proves fatal to animals, in countries where the winters are very severe. Thus seven thousand Swedes perished at once, in attempting to pass the mountains which divide Norway from Sweden. It is not necessary, indeed, that the cold, in order to prove fatal to human life, should be so very intense as has been just mentioned. There is only requisite a degree somewhat below 32° of Fahrenheit, accompanied with snow or hail, from which shelter cannot be obtained. The snow which falls upon the clothes, or the uncovered parts of the body, then melts, and, by a continual evaporation, carries off the animal heat to such a degree, that a sufficient quantity is not left for the support of life. In such cases, the person first feels himself extremely chill and uneasy; he begins to grow listless, unwilling to walk or use exercise to keep himself warm; and at last turns drowsy, sits down to refresh himself with sleep, but wakes no more.

An instance of this was seen not many years ago at Terra del Fuego; where Dr. Solander, with some others, having taken an excursion up the country, the cold was so intense, that one of their number died. The Doctor himself, though he had warned his companions of the danger of sleeping in that situation, yet could not be prevented from making that dangerous experiment himself; and though he was awaked with all possible expedition, his body was so much shrunk in bulk, that his shoes fell off his feet, and it was with the utmost difficulty that he was recovered.

In those parts of the world where vast masses of ice are produced, the accumulation of it, by absorbing the heat of the atmosphere, occasions an absolute sterility in the adjacent countries, as is particularly the case with the island of Iceland; where the vast collections of ice floating out from the Northern Ocean, and stopped on that coast, are sometimes several years in thawing. Indeed, where great quantities of ice are collected, it would seem to have a power like fire, of both augmenting its own intenseness and that of the adjacent bodies.

Astonishingly Expansive Force of Freezing Water.—Although cold, in general, contracts most bodies, and heat expands them, yet there are some instances to the contrary, especially in the extreme cases or states of these qualities of bodies. Thus, though iron, in common with other bodies, expands with heat; yet, when melted, it is always found to expand in cooling again. Thus also, though water expands gradually as it is heated, and contracts as it cools, yet in the act of freezing it suddenly expands again, and that with an enormous force, capable of rending rocks, or bursting the very thick shells of metal, &c. A computation of the force of freezing water, has been made by the Florentine academicians, from the bursting of a very strong brass globe or shell by freezing water in it; when, from the known thickness and tenacity of the metal, it was found that the expansive power of a spherule of water only one inch in diameter, was sufficient to overcome a resistance of more than twenty-seven thousand pounds, or thirteen tons and a half.

Such a prodigious effect of expansion, almost double that of the most powerful steam-engines, and exerted in so small a mass, seemingly by the force of cold, was thought a very material argument in favour of those who supposed that cold, like heat, is a positive substance. Dr. Black’s discovery of latent heat, however, has afforded a very easy and natural explication of this phenomenon. He has shewn, that, in the act of congelation, water is not cooled more than it was before, but rather grows warmer: that as much heat is discharged and passes from a latent and a sensible state, as, had it been applied to water in its fluid state, would have heated it to 135°. In this process, the expansion is occasioned by a great number of minute bubbles suddenly produced. Formerly these were supposed to be cold in the abstract, and to be so subtile, that, insinuating themselves into the substances of the fluid, they augmented its bulk, at the same time that, by impeding the motion of its particles upon each other, they changed it from a fluid to a solid. But Dr. Black shews, that these are only air extricated during the congelation; and to the extrication of this air he ascribes the prodigious expansive force exerted by freezing water. The only question, therefore, is, by what means this air comes to be extricated, and to take up more room than it naturally does in the fluid? To this it may be answered, that perhaps part of the heat, which is discharged from the freezing water, combines with air in its unelastic state, and, by restoring its elasticity, gives it that extraordinary force; as is seen in the case of air suddenly extricated in the explosion of gunpowder. The degree of expansion of water, in the state of ice, is by some authors computed at one tenth of its volume. Oil and quicksilver shrink and contract after freezing. Mr. Boyle relates several experiments of vessels made of metals, very thick and strong; in which, when filled with water, closely stopped, and exposed to the cold, the water being expanded in freezing, and not finding either room or vent, burst the vessels. A strong barrel of a gun, with water in it, close stopped and frozen, was rent the whole length. Huygens, to try the force with which it expands, filled a cannon with it, whose sides were an inch thick, and then closed up the mouth and vent, so that none could escape; the whole being exposed to a strong freezing air, the water froze in about twelve hours, and burst the piece in two places. Hence mathematicians have computed the force of the ice upon this occasion; and they say, that such a force would equal twenty-seven thousand seven hundred and twenty pounds.

Major Edward Williams, of the Royal Artillery, made many experiments on the force of freezing water, at Quebec, in 1784-1785. He filled all sizes of bomb shells with water, then plugged the fuze-hole close up, and exposed them to the strong freezing air of the winter in that climate; sometimes driving in the iron plugs as hard as possible with a sledge hammer; and yet they were all thrown out by the sudden expansion of the water in the act of freezing, like a ball shot by gunpowder, sometimes to the distance of between four and five hundred feet, though they weighed near three pounds; and when the plugs were screwed in, or furnished with hooks or barbs to lay hold of the inside of the shell by, so that they could not possibly be forced out, in this case the shell was always split in two, though the thickness of the metal of the shell was about an inch and three-quarters. Through the circular crack, round about the shells, where they burst, there stood out a thin film or sheet of ice, like a fin; and in the cases where the plugs were projected by freezing water, there suddenly issued out from the fuze-hole a bolt of ice of the same diameter, and stood over it to the height sometimes of eight inches and a half.